Spa shell



FIG. 1 is a perspective view of a spa shell showing our new design;

FIG. 2 is another perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a cross-sectional view thereof, taken in the direction of line 4-4 of FIG. 3;

FIG. 5 is a cross-sectional view thereof, taken in the direction of line 5-5 of FIG. 3;

FIG. 6 is a cross-sectional view thereof, taken in the direction of line 6-6 of FIG. 3; and,

FIG. 7 is a cross-sectional view thereof, taken in the direction of line 7-7 of FIG. 3.

The broken lines show portions of the spa shell that form no part of the claimed design. 

CLAIM The ornamental design for a spa shell, as shown and described. 